This subproject will investigate the structural aspects of force transfer in bladder smooth muscle. Using both an animal model of obstruction (rabbit) and cell cultures that are subjected to defined levels of strain, the structure and stability of the Tension Transfer Apparatus in bladder smooth muscle cells ( likely the smooth muscle equivalent of the dystrophin-glycoprotein complex (DGC) in striated muscle) will be investigated using immunohistochemistry at both the light (confocal scanning microscopy) and electron microscopic levels. The Specific aims for project 1 are: 1. To characterize the dystrophin-glycoprotein complex in bladder smooth muscle during obstruction using immunochemical, ultrastructural and biochemical approaches. 2.To characterize expression of dystroglycan & sarcoglycans as a consequence of mechanical loading. Our hypothesis is that a normal Tension Transfer Apparatus is required for transfer of tension across the smooth muscle cell membrane and that obstruction physically disrupts or disturbs this architecture thereby compromising the ability of the muscle cell to distribute the force developed actively.